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It's unlikely an urban fire department is set up for any significant amount of drafting (pulling water from surface sources), if it's something they can do at a
by stcredzero 8y ago
It's unlikely an urban fire department is set up for any significant amount of drafting (pulling water from surface sources), if it's something they can do at all.
My understanding, which is probably quite out of date, is that it's mostly harbor firefighting boats which had this ability.
A coworker of mine points out that many of the San Francisco manholes are actually covers for cisterns of water, which exist primarily for fighting fires after an earthquake possibly takes out the water mains and starts many fires. I should hope that San Francisco fire trucks can draft water to use these.
- i_am_proteus 8y agoFormer (volunteer) firefighter here: Park the truck next to the cistern. Connect a length of hose to the pump supply, drop the hose into the cistern. The pump will move water until it loses suction pressure.
- JshWright 8y agoNot just any hose though, you need rigid walled hose. Regular fire hose would just collapse flat under suction. https://en.wikipedia.org/wiki/Hard_suction_hose https://en.wikipedia.org/wiki/Hard_suction_hose
- stcredzero 8y agoIs the hose to be dropped into the cistern different from the other hoses? I would expect it to be reinforced, such that it wouldn't collapse from air pressure. Hoses downstream from a high pressure pump wouldn't need such reinforcement. However, it's different upstream from such pumps.
- evasote 8y agoYou can recognize the cisterns because there are big (like 20 ft in diameter) brick circles inlaid into the street in SF to mark the cisterns. Neat once you know what to look for